The 30 Rock star revealed during an interview on The Howard Stern Show he had been offered the part of a villain in one of the blockbuster movies, which include Iron Man, Thor and Avengers Assemble, but refused to divulge which character it was.

Alec said: "I have [been offered a role in a superhero movie], but I won't mention which one.

"I don't want to undo somebody because they hired someone else to do it. But they asked me to play a villain in one of these Marvel Comics movies."

The 55-year-old actor - currently starring with Cate Blanchett in Woody Allen's new film Blue Jasmine - said he rejected the role because of scheduling problems.

Alex explained: "I wasn't available. They wanted me to work a certain time. And because of my wife's pregnancy, I had to turn down two films this summer that I wanted to do."

The actor married yoga instructor Hilaria Thomas last summer and announced earlier this year they are expecting their first child.